Update on acute respiratory distress syndrome�s pathology. Recent insights into in vivo alveolar regeneration

Abstract

Acute Respiratory Distress Syndrome (ARDS) is a type of acute lung injury characterized on histology by a pattern of Diffuse Alveolar Damage(DAD). Since patients who survive their critical illness generally recover a normal respiratory function, ARDS is regarded as a remarkable example of in vivo alveolar regeneration and mice with chemical or viral-induced ARDS represent a useful experimental model for studying these processes. Recent studies opened new insights into the mechanisms of alveolar regeneration, partly challenging the traditional hypothesis that identifies alveolar type II cells as the progenitor of the alveolar epithelium. Particularly, we proposed Krt14 as a robust marker of alveolar regeneration and repair, since its expression in the lung parenchyma is only found in pathological conditions during pneumocyte proliferation after severe damage. A better understanding of the processes that regulate in vivo alveolar regeneration would make it possible to revolutionize the therapeutic approach to patients with respiratory chronic disease, paving the way to the so called “regenerative lung medicine”.